Re^2: Defining classes and inheritance using packages within a single .pl file, without creating modules

In general, I agree with your excellent advice, jbert, except for this minor point:

However, I'd personally do neither of those. The best way these days to declare inheritance is use base, which also has the handly property of being a compile-time construct.

IMO base is a crap module, it tries to handle both loading external files and inline packages, but it tries Too Much Magic™ and in some cases it may fail. It's failed many times for me in the past. I don't trust it any more.

As a result, you may have to reorder the definition for your packages and possible even add a $VERSION variable (in an inline package!). All that to please base. Yuck.

I wish we could bypass the magic, and explicitely tell it to load a module, or just skip that phase.

If it wasn't for that annoyance, base would indeed work very well, for the reasons you give.

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Re^3: Defining classes and inheritance using packages within a single .pl file, without creating modules by jbert (Priest) on Nov 29, 2006 at 12:06 UTC
That's interesting - and serves as an additional data point that consensus on current perl OO "best practice" is a bit limited at the moment. Yes, TIMTOWDI, but that can be confusing for newcomers. Do you think that these tutorials are still current? (Actually, I should have linked to these at first, sorry about that). By the way, would you care to elaborate on base's failure modes? Since you've caused me to look more closely, I can see how it might hurt if you're defining a module inline with the same name as one available as a seperate file via require - is that the main issue?	[reply]
Re^4: Defining classes and inheritance using packages within a single .pl file, without creating modules by bart (Canon) on Nov 29, 2006 at 12:24 UTC
I'm not sure how base has evolved over the years, but I've had problems where it died complaining it couldn't locate a module where the package was inline in the script further down, and it may indeed load an unwanted module of the same name (B is a favourite example) under similar circumstances. Fun for the whole family. Checking `$VERSION` in a package, to check if the package exists, is not the best way to tackle the problems, IMO.	[reply] [d/l]
Re^5: Defining classes and inheritance using packages within a single .pl file, without creating modules by Anonymous Monk on Nov 29, 2006 at 13:01 UTC
Don't blame base. If you're going to inline modules that use base, do it properly.	[reply]
Re^3: Defining classes and inheritance using packages within a single .pl file, without creating modules by adrianh (Chancellor) on Nov 30, 2006 at 01:15 UTC
IMO base is a crap module, it tries to handle both loading external files and inline packages, but it tries Too Much Magic™ and in some cases it may fail. It's failed many times for me in the past. I don't trust it any more. Use it all the time. Never had a problem with it :-) I don't really think it's that magical. Two rules: If the package is already loaded - use it Otherwise, try and use it.	[reply]
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